We were given an accordion in beautiful shape that has been transferred a few times so I've lost it's history. It is in terrific shape and has to be at least 50 years old. It says "LARGO" on the top and "Model Grandioso / Made in Italy" on the bottom. Is there any information about this instrument online? A good way to ID the year? Also does anybody know if the chords are the Stradella system or something else?